groundwater arsenic contamination and associated health risks in bihar, india

the extent of groundwater arsenic (as) contamination and associated health-risks were studiedin the four villages: chaukia and terahrasiya (vaishali); mamalkha and masharu (bhagalpur) in bihar, india.groundwater samples were tested using the standard silverdiethyledithiocarbamate method at 520nm bythermo uv-1 spectrophotometer. the as levels in both the districts exceeded the who standard of 10μg/lfor drinking water with a maximum value of 20μg/l in vaishali and 143μg/l in bhagalpur. however, the faostandard of 100μg/l of as for irrigation water was only exceeded in bhagalpur. the calculated range of thehazard index (hi) for vaishali was 0.9 to 10, and for bhagalpur was 10.40 to 40.47. both ranges exceed theaccepted normal toxic hi of 1.00. the cancer risk was derived as 1-5/1000 people to 5-16/10,000 people invaishali, and 7-21/1000 and 5-16/1000 people in bhagalpur. prevalence of skin pigmentation was double invaishali in comparison to bhagalpur. the analysis of principal components showed that only two componentshad a fundamental role in defining variance for cancer risk assessment. a more extensive screening of ascontamination of groundwater and a follow-up clinical study are necessary to accurately assess the likelihoodof as-related cancers in these districts.